CAlories on Atkins??

[Aways2Go]

Re: CAlories on Atkins??

Georgiana, your comment made me wonder more about this, which I truly don't know the answer to and maybe you or someone else will have some thoughts to share ...

Scientifically speaking, if a person's ideal body weight is say, 125 pounds, but they weigh 225 pounds so they have 100 pounds of excess body fat...

does that 100 pounds of pure body fat have the same basic nutritional requirements as that other 125 pounds of body mass that is their 'baseline'? I can't imagine it actually does. If it did, though, then that would mean a person who should weigh 125 pounds but has 100 pounds of excess fat would have the same basic nutritional requirements as a fit 225 pound person without much excess body fat. That surely can't be the case, can it? Surely fat cells do not actually have the same nutrient requirements as organ tissue, muscle, bone, etc.

Even with regard to just calories and not even including overall nutrient intake, muscle burns more calories than fat, right? So it stands to reason, in my very simplified and off-the-cuff thought process here, that the 225 pound person with 100 pounds of fat to lose would not need the same caloric level as the relatively fit 225 pound person. Maybe somewhere in between the two levels (using the 10 to 12x guideline) - something between the ideal body weight and the current weight?

[Suzanne_H]

Re: CAlories on Atkins??

The reason I was approaching 300 pounds so quickly was that I was eating about 3000 calories a day. Imagine that. LOL

[Georgiana]

Re: Calories on Atkins??

Aways, when I said "nutritional requirements" I was not referring to say, the amount of calcium in one's diet, but more to macronutrients (in the end, calories).

As I've said, to me it does not make sense for someone who is 300+ lbs to consume the same number of calories as someone who is 150 lbs. More energy is required to move around 150 extra lbs than (more or less) none.

Of course, if someone is 170 lbs and wants to get down to 150, the chances to undereat by calculating caloric needs based on 150 lbs are small. But if someone is 300+ lbs, I'm not so sure.

There is some debate as to whether caloric needs should be calculated based on ideal or current weight. In some diet books we have at the library, the ideal weight is used (they are for low fat diets though). In the studies on low-carbohydrate diets I've read, it's done in pretty much any way you can imagine (based on current weight, on ideal weight, or unlimited calories). But if you want to look at numbers... these are from two papers I have handy now:

Study .................................................. Average weight (lbs) ................... Average caloric intake (kcal) .............. Length of the study ................ Average weight loss (lbs)

Westman et al. 2002 ............................. 192 +/- 24 ........................................ 1447 +/- 350 ...................................... 6 months ........................................ 20 +/- 12
Volek et al. 2002 .....................................174 +/- 18 ......................................... 2334 +/- 368 ...................................... 6 weeks ............................................ 5 +/- 2

In Westman et al. it says, "aerobic exercise was encouraged at least 3 times per week (at least 20 min per session)." Fat mass decreased by 14 lbs. Nonfat mass decreased by 7 lbs.

In Volek et al., 1 subject was sedentary, 5 did aerobic exercise 2-4 times per week (20-60 min), and 6 did aerobic exercise 3-5 times per week (15-90 min) and resistance exercise 2-6 times per week (45-120 min). Fat mass decreased by 7 lbs and soft tissue lean body mass increased by 2.5 lbs.